// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//      Lookup tables.
//      Do not try to look them up :-).
//      In the order of appearance:
//
//      int finetangent[4096]   - Tangens LUT.
//       Should work with BAM fairly well (12 of 16bit,
//      effectively, by shifting).
//
//      int finesine[10240]             - Sine lookup.
//       Guess what, serves as cosine, too.
//       Remarkable thing is, how to use BAMs with this?
//
//      int tantoangle[2049]    - ArcTan LUT,
//        maps tan(angle) to angle fast. Gotta search.
//
//-----------------------------------------------------------------------------

#ifndef __TABLES__
#define __TABLES__

#include "m_fixed.h"

#define FINEANGLES      8192
#define FINEMASK        (FINEANGLES-1)

// 0x100000000 to 0x2000
#define ANGLETOFINESHIFT 19

// Effective size is 10240.
extern  fixed_t         finesine[5*FINEANGLES/4];

// Re-use data, is just PI/2 pahse shift.
extern  fixed_t*        finecosine;

// Effective size is 4096.
extern fixed_t          finetangent[FINEANGLES/2];

// Binary Angle Measument, BAM.
#define ANG45           0x20000000
#define ANG90           0x40000000
#define ANG180          0x80000000
#define ANG270          0xc0000000

#define SLOPERANGE      2048
#define SLOPEBITS       11
#define DBITS           (FRACBITS-SLOPEBITS)

typedef unsigned angle_t;

// Effective size is 2049;
// The +1 size is to handle the case when x==y
//  without additional checking.
extern angle_t          tantoangle[SLOPERANGE+1];

// Utility function,
//  called by R_PointToAngle.
int
SlopeDiv
( unsigned      num,
  unsigned      den);

#endif  // __TABLES__
